Research: Elderd Lab

I am primarily interested in the indirect effects of predators on pathogens of their prey and vice-versa.

Research1

This page has a list of the projects I am currently working on myself and with collaborators. If you are interested in collaborating in some way, email me and we’ll see what happens!

In the Elderd Lab:

1 Predator, prey, and pathogen interactions (Figure from Flick et al 2016)

My dissertation work focuses on the effects of virus infected soybean loopers on spined soldier bugs. To this effect, I conducted a meta-analysis (see publications) to see what had been done in this field. What I found was that, in biocontrol communities with a pathogen (virus or fungus) and a predator, predators are negatively influenced (decreased egg production and longevity) by consuming infected prey compared to healthy prey. Intuitively, I found that parasitoids avoid infected prey while true predators (e.g., spiders) have no preference (Flick et al 2016). This project serves as chapter one of my dissertation.

In chapter two, I use lab and field studies to try to tease apart the interactions between predators and pathogens. I used lab studies to investigate spined soldier bug (SSB) preference in every way possible (i.e., dead soybean loopers, live soybean loopers, in trays, on plants, etc). I have found no differences in SSB preference for healthy or infected soybean loopers. This project is nearing completion and the data will be included in a publication in the near future. Another project nearing completion that will likely be included in the same manuscript is fitness data. I have collected fitness data for two populations of spined soldier bugs and (again as predicted from the meta-analysis) found that SSBs take longer to develop, do not live as long, and produce fewer offspring when reared on infected soybean loopers. Much of this work is with collaboration from Dr. Tom Coudron of the USDA-ARS in Columbia, MO.

IMG_20150616_132019_715    cropped-img_20150329_195556_617.jpg   Preadotrs in a cup.png

The next part of chapter 2 focuses on field work investigating how predators change the transmission rate of the virus. I use what we call ‘bugs in bags’ (see left image below) plots to neatly control virus density, predator presence, and the number of healthy caterpillars placed in each bag. I collected data on the proportion of recovered caterpillars that develop virus infection. I am looking at consumptive and non-consumptive effects. This project will have the final replicate completed this summer (2017). I am excited to finally complete this project after four years of varying degrees of success (each less than 100%).

All Bags     Soldier bug eats cat

The final chapter of my dissertation is creating and analyzing a mathematical model that describes this system. I am using a series of equations to track each population (predators, prey, infected prey, cadavers) and various analytical techniques to look at model stability and equilibria, among other things.

2 Cats have eyes

This project was started by our previous undergraduates David Clark and Olivia Barry. We are investigating how eyespots deter predation using new techniques for creating clay caterpillars.

3 Misc

With Matt Faldyn (Elderd Lab mate): Monarch butterfly life-table response experiment

With Sama Shretsha (CU – Boulder Dukic Lab): Mathematical modeling of fall armyworm virus

With Tom Coudron: Fitness effects of virus infected hosts on parasitoids